Fishway



All@ 8, 1939 H. B. HOLMES Er A1. 2,168,341

FISHWAY Filed March l, 1938 3 Sheets-Sheet 1 FOEBAY- l/u,

Aug. 8, 1939.

H. B. HOLMES Er AL- l FISHWAY Filed March l, 1938 3 Sheets-Sheet 2 n.a.. .0.0 w 0 0 ATTORNEY Patented Aug. 8, 1939 UNITED lSTATES PATENTOFFICE FISHWAY Secretary of War Application March 1, 1938, Serial No.193,292

6 Claims.

(Granted under the act of March 3,Y 1883, as amended April 30, 1928; 370O. G. '757) This invention described herein may be manufactured and usedby or for the Government for governmental purposes, without the paymentto us of any royalty thereon.

This invention relates to improved methods and structures for attractingfish into shways at dams and other obstructions to the passage of iishin their migrations up stream.

In the development of the art of shways attention has been directed mostexclusively to providing means by which fish after entering the devicemay climb or be carried to the water level above the obstruction withoutexcessive exertion on the part of the fish. Very little attention hasbeen given to the problem of inducing the fish to enter the shway. Itgenerally has been assumed that the quantity of water allowable to afishway must be comparatively small. It naturally has followed that theentrance to the fishway also must be correspondingly small. As a resultof this trendof development, the greatest single cause of failure andineiciency in shways is the failure of the fish to find the entrance,rather than their inability to negotiate the passage provided,

The fact that fish eventually find the entrance to a iishway does notjustify the conclusion that the device is successful. Fish frequentlyare seriously injured in their efforts to surmount the obstructionbefore iindingthe entrance to the shway. In the case of the Pacificsalmon, which do not feed while making their upstream migration to thespawning grounds, a prolonged delay at an obstruction while the fish isseeking a way to pass, may cause an excessive expenditure of the shslimited supply of energy stored in the form of fat, with the result thatthe fish may be unable to complete its migration and perform therigorous act of spawning.

Fish such as salmon and trout, which are strong swimmers, are foundincomparatively rapidly flowing streams and are inclined uponencountering an obstruction to seek a route of passage by way of thedischarge through the spillways and power wheels, rather than to searchfor a route leading from the areas of quiet water. The shways,therefore, must compete with these points of discharge in attracting thefish. Du

to limitations in cost, structural design, space, and water economy, thesize of a shway usually is limited. The quantity of water that can becarried by these limited structures and the area over which this watercan be distributed at the entrance, are so slight that the attractionfurnished by the iishway is insignificant when compared with the counterattractions represented by the spillway and power wheel discharges.

The effectiveness of a shway entrance depends to a great extent upon itslocation with respect to the obstruction and the counter attractions.For example, it is desirable in general to place the fishway entranceadjacent to the spillway or draft tube openings where advantage maybetaken of the concentration of fish at these counter attractions. Theexact position of these favorable locations usually varies with powerhouse operation, spillway regulation, and river stages. Conventionalshway practice usually does not permit flexibility in the nature andposition of shway entrance to correspond with these differingconditions.

The primary yobject of the invention is to improve the effectiveness ofa iishway entrance by increasing the size of the entrance andintroducing into it an auxiliary supply of moving water much greater inquantity than economically can be passed through the fishway proper,this auxiliary water being introduced into the entrance in such a mannerthat it does not constitute a counter attraction, but leads the fish inthe direction to be followed in passing through the iishway.

Another object is to provide means of maintaining the effectiveness of ashway entrance in spite of extreme fluctuations in river flow andaccompanying fluctuations in tail-race elevation.

Another object is to provide means of controlling the quantity andvelocity of water discharge through the entrance of iishways.

Another object is to improve the effectiveness ofal iishway by providingmultiple entrances varied in nature and position with relation to theobstruction and the flow of water over or through the obstruction.

Another object yof this invention is to provide a powerhouse damconstruction wherein a series of fish entrances are arrangedsubstantially across the downstream face of the construction and abovethe draft tubes, communicating with a collection bay extending the fulllength of the dam, the collection bay terminating at: one end in anentrance bay leading to a plurality of fish locks.

Other objects relating to the details of construction, combination andarrangement of parts will hereinafter appear in the description tofollow.

Referring more particularly to the accompanying drawings in whichcorresponding parts are indicated by similar reference characters:

Fig. 1 is a perspective View of a power-house 55 dam construction,illustrating the arrangement of the fish entrances above the draft tubesand showing the collection bay extending the full length of the dam andcommunicating at one end with an entrance bay leading into a pair of shlocks.

Fig. 2 is a horizontal section taken on the line of 2 2 of Fig. 1.

Fig. 3 is a fragmentary sectionized perspective, illustrating theinterior arrangement of the collection bay and showing the conduitarrangement for supplying additional water tothe co1- lection bay; and

Fig. 4 is a transverse vertical section taken on the line 4-4, of Fig.3.

In the illustrated embodiment characterizing this invention I indicatesa power-house dam construction consisting of, an upstream wall Ia, adownstream wall 2a, an end wall 3a, a series of laterally spacedfoundation members 4a, extending between the walls and adapted to serveas supports for additional sections of the powerhouse, a water supplysection 5a, and fish lifts 3 and 4 in controlled communication at theirupper ends with the forebay 6 and at their lower ends with entrance bay5 formed in the portion 6a of downstream wall 2a., as clearly shown inFig. l of the drawings. The lower portion of the downstream wall 2a isprovided with a series of draft tubes 8 which are adapted to dischargeinto the tailracel 9. These tubes establish communication between theforebay 6 and tailrace 9 via suitable turbines (not shown) adapted to belocated in the power-house 2, as will be understood without furtherdiscussion.

Within the upper portion of the downstream wall and coextensive with itslength is a collection bay or channel I9. This collection bay or channelI9 which is dened by the front wall portion la, the rear wall portion 8aand the roof portion 9a of downstream wall 2a, extends at one end intothe portion 6a and opens into entrance bay 5, as clearly shown in Fig. 2of the drawings. The opposite end of the channel I9 is adapted to beconnected to suitable flshways (not shown). 'Ihe roof portions of thedraft tubes 8, which as shown in Figs. 3 and 4 of the drawings, are inthe form of inclined slabs I0, not only serve as the roofs of the drafttubes but also function collectively as the floor structure for apassage Illa which extends lengthwise of the downstream wall 2a, abovethe draft tubes S and below the collection bay of channel I9. PassageIlla is divided into a series of diffusion chambers II, one of which isdisposed above each of the draft tubes.

Within an opening I Ia formed in the rear wall portion 8a of thedownstream wall 2a and irnmediately to the rear of collection bay I9 isa conduit I2, having one end closed and the other in controlledcommunication with forebay 6 through the vertically disposed passage I2in the water supply section 4a, as clearly shown in Fig. 1 of thedrawings. The upper end of passage I2 opens into forebay 6 through acontrol passage (not shown). The lower` portion of the conduit I2adjacent the diffusion chambers II is in communication with saidchambers through apertures I4, which are adapted to be controlled byvalves I5 operated by handwheel mechanisms. I6.

An additional diffusion chamber II', also in valve controlledcommunication with the forebay 6, through passage I3, is providedimmediately in front of the entrance to the sh locks 3 and 4'.

Each of the diffusion chambers as II` is provided with an aperturedpartition I'I substantially horizontally disposed, and spaced apart fromthe slab I0. Suitable grillage I8, having apertures of a size torestrain fish from entering the diffusion chamber is suitably spacedabove the apertured partition II. The flow of water from the conduit I2is introduced into the diffusion chambers I I at a rate below that whichwould lure the fish into vainly attempting to follow the current passingthrough the grillage I 8. The amount of water introduced from theconduit I2 is controlled to maintain substantially uniform directionalvelocity through the collection bay I9.

All of the diffusion chambers open, via the apertured partition I1 andthe grillage I8, into the collection bay I9, which has one extremityopening into entrance bay 5 and the other in controlled communicationwith a suitable fishway (not shown). These flshways, which may be in theform of fish ladders or shlifts serve to effect a transfer of the fishfrom the collection bay to the forebay, as will be understood withoutfurther discussion.

The collection bay I9 may be provided with suitable means as stop logs20, whereby any portion of the collection bay may be isolated forinspection, cleaning, and/or repair.

Each of the diffusion chambers I I may be provided with suitabledrainage means as conduit 2I, whereby it may be drained to facilitateinspection, cleaning, and/or repairs.

The front wall portion Ia of downstream wall 2a is formed with a seriesof spaced columns 22. Adjustable stop logs 23 are suitably disposedbetween the columns 22 and cooperate with regulating gates 24 to providemeans whereby the elevation of the water within the collection bay maybe suitably controlled to accommodate variations in tailrace level andto provide any desired localization of flow. Suitable traps comprised ofclosely spaced curved rods Z'extending upwardly and toward thecollection bay are disposed on the top of each regulating gate 24.Submerged openings, as 23a, may be provided in the adjustable stop logs23 by the substitution of suitable apertured members.

The collecting system as described conveys the fish to a pair of fishlocks 3 and 4. It is to be understood that any satisfactory type offishway may be substituted for the sh locks.

In case the economy of water for use in generating power is aconsideration of importance, the auxiliary water supplied throughconduit I2 may be pumped from the tailrace by low head pumps at a lesserexpenditure of energy.

The operation of the structure described immediately above is asfollows:

Water flowing from one of the fish locks 3 or 4 is augmented by a flowof water from the diffusion chamber II situated immediately in front ofthe lock entrance. The flow from the diffusion chamber II is regulatedin accordance with the existing tailrace level so as to produce thedesired velocity along the collection passage I9. A part of waterflowing along the closed portion of the collection passage is lost tothe tailrace over the first Weir gate 24. A corresponding quantity ofwater is added through the diffusion chamber I I which is opposite thisfirst Weir gate. By a repetition of this procedure of adding water fromthe diffusion chambers II as it is lost over the wer gates 24, thequantity of water and therefore the velocity passing along the entirelength of the collection bay can be maintained in any desired constantcondition.

Fish attracted by the water owing over the weir gates 24, swim over oneof these gates into the collection bay I9. Continuing to swim againstthe current, the fish are directed in a normal manner to the fish locks3 and 4. The course of the fish in passing along the collection bay I9is not influenced by the iiow of water introduced through the diusion'chambers Il, because the velocity at which this water is introduced isso much lower than the longitudinal velocity in the collection bay thatit is not distinguishable to the fish. The trapping means on theregulating gates 24 is provided to assure that the fish while passingalong the collection bay I9 will not return to the tailrace.

The operation of any of the hydraulic power equipment will beaccompanied by a flow of water through certain of the draft tubes 8. Ifbut a single turbine is in operation, the flow will be confined to butone draft tube, whereas if all of the turbines are in operation, theflow will emerge from all of the draft tubes.

This iiow constitutes a counter attraction with which the shway mustcompete in attracing the fish. The most favorable position for thefishway entrances depends upon the number of units that are in operationand the hydraulic conditions produced by them. It frequently isimpossible to determine in advance for each mode of powerhouseoperation, just where will be the most favorable positions for theiishway entrances. The collecting system therefore is designed toprovide a plurality of entrances any or all of which may be used to suitprevailing conditions. The plurality of entrances with theiraccompanying auxiliary water supplies through diffusion chambers Il alsopermits for the attraction of fish, the use of a quantity of water muchgreater than could be provided by the sh locks 3 and 4 or any otherconventional type of fishway.

While the structure shown and described is the preferred embodiment ofthe invention, it is to be understood that the general structure,arrangement, and combination of parts may be altered by those skilled inthe art without departing from the spirit of the invention as dened bythe following claims.

Having thus described the invention, what we claim and wish to secure byLetters Patent is:

1. In a structure of the class described, the combination of a damprovided with a forebay and a tailrace, a collection bay disposedadjacent said dam and provided with a portal leading to the tailrace, aweir disposed in said portal, and a shway disposed between thecollection bay and the forebay for effecting the transfer of fishbetween the collection bay and the forebay.

2. In a structure of the class described, the combination of a damprovided with a forebay and a tailrace, a collection bay disposedadjacent said dam and provided with a portal leading to the tailrace, anadjustable Weir disposed in said portal, a diffusion 'chamber disposedbelow the collection bay, an apertured partition disposed over thediffusion chamber, a grill disposed between the apertured partition andthe collection bay, a conduit effecting controlled hydrauliccommunication between the forebay and the diffusion chamber, and aiishway disposed between the collection bay and the forebay foreffecting the transfer of sh between the collection bay and the forebay.

3. In a structure of the class described, in combination with a damprovided with a forebay and a tailrace, a collection bay disposedadjacent said dam and provided with a plurality of portals leading tothe tailrace, a plurality of adjustable weirs disposed one each in eachof said portals, a diffusion chamber disposed below the collection bayand in open communication therewith, a conduit effecting controlledhydraulic communication between the forebay and the diffusion chamber,and a fishway disposed between the collection bay and the forebay.

4. In a power-house dam construction the combination with a dam providedwith a forebay, a tailrace and a downstream wall adjacent the tailrace,of a collection bay within the wall and in controlled communication withthe forebay through a series of diffusion chambers underlying thecollection bay, said collection bay opening into the tailrace through aportal in the wall, an adjustable weir within the portal and a shwaydisposed between the collection bay and the forebay for effecting atransfer of fish therebetween. v

5. In a power-house dam construction, the combination with a damprovided with a forebay, a tailrace and a downstream wall adjacent thetaiirace, of intercommunicating collection and entrance bays within thewall, the collection bay being in controlled communication with theforebay and opening into the tailra'ce through a portal formed in thewall, an adjustable Weir disposed within said portal and a shway betweenthe entrance bay and the forebay for effecting the transfer of fish fromthe entrance bay to thev forebay.

6. In a power-house dam construction, the combination with a damprovided with a forebay, a tailrace and a downstream wall adjacent thetailrace, of a series of draft tubes formed in the wall, said tubesbeing in controlled communication with the forebay and discharging intosaid tailrace, a collection bay within the wall and in controlledcommunication with the forebay, said collection bay extending lengthwiseof the wall opening into the tailrace through a series of portals formedin said wall above the draft tubes, an adjustable weir in each of saidportals and a iishway disposed between the collection bay and theforebay for effecting a transfer of fish between said collection bay andsaid forebay.

HARLAN B. HOLMES. HENRY F. BLOOD. MILO C. BELL.

